1. Technical Field
The invention generally relates to a device and a method for signal processing, and more particularly, to a device and a method for signal processing which can selectively initiate a reduction process according to the characteristic of noise components present within an input signal.
2. Description of Related Art
With the development of biomedical engineering, doctors are able to make convincing diagnoses according to different sorts of medical reports produced by biomedical inspection instruments. For example, the instruments may obtain a physiologic signal, such as an electrocardiogram (ECG) signal, through electrodes directly attached to a patient's chest, arm, or leg. Then, the physiological signals can be detected and transmitted to processing device for further processing.
Typically, the amplitude of the ECG signal transmitted from electrodes is usually measured around millivolts, so that noise components within the ECG signal may significantly affect the actual waveform of the ECG signal. Thus, it is almost meaningless to analyze the ECG signal with the presence of noise components in the ECG waveforms. In order to deal with this sorts of dilemma, high pass filters or band pass filters are generally used to conduct a noise reduction process to reduce the noise components caused by environment, such as power-line interference, ambient electromagnetic activity or movements of electrodes. Besides, signal processing techniques are also considered useful for reducing the noise components of the ECG signal, such as baseline wander effect and motion artifact. As reducing noise components within the ECG signal may be one of the most critical biomedical issues nowadays, it is worthy to develop a signal processing device and a signal processing method which can filter out the noise components.